The use of medical guide wires (or “guide wires”) is ubiquitous in modern era, non-invasive, medical practice including cardiac catheterization and interventional radiology disciplines and the practice of endo-vascular surgery.
An accepted method of accessing the interior of a blood vessel involves placing a needle inside a short cannula, and then placing the needle and cannula into the blood vessel with subsequent extraction of the needle, but retention of the short cannula. This method is used for both diagnostic and endo-vascular surgical procedures. Once the needle is removed from the blood vessel, the cannula becomes an open access to the vasculature and blood will escape through the cannula unless the cannula is capped. Once a cannula has been placed in a blood vessel using this or any other method, it is common for a general-purpose guide wire, such as a 0.018-inch diameter wire or a flexible, 0.035 inch×4.5 mm regular J guide-wire (which, as known to those skilled in the art is a guide wire having a single, J-shaped, flexible tip of 4.5 mm in length) to be inserted into the cannula and into the blood vessel. At that point, the cannula is removed leaving the guide wire in the blood vessel an extending outward through percutaneous puncture. The intra-vascular location of the guide wire is usually confirmed with fluoroscopy or other suitable method at this point.
Once confirmed that the guide wire is intra-vascular, a sheath and dilator may be passed over the guide wire. The dilator is then removed and the sheath is flushed with heparin. Once that is completed, a guide wire exchange may be made, whereby the general-purpose guide wire may be replaced with another guide wire. The new guide wire may be a long J guide wire, a long regular or firm, angled or straight, 0.035 inch guide wire or a long similar featured floppy-tipped stiff guide wire depending upon the physician, choice, and of any length that may be desired by the physician to accomplish whatever goal is required. On occasions for example in selected intra-aortic procedures, a very stiff wire, sometimes called a “coat-hanger” wire, such as a Lindquist or Amplatz wire is selected (for endo-vascular repair of an abdominal aortic aneurysm for example.)
Most medical guide wires presently come prepackaged in a single use sterile pack consisting of an outer layer on one side of the sterile pack, of white backing paper that is rugged and difficult to tear, and on the other side, transparent, non-tearable cellophane. The cellophane and the white backing paper are heat-sealed and at one end, a peelable seal is made. To open the sterile pack, the chevron seal is grasped between both hands and the two sheets of paper are peeled apart. The medical guide wire is then passed from the sterile pack to the operator.
Presently, a single medical grade guide wire is stored in a circular coil of a capillary plastic tube sufficient to contain the length of the guide wire that has been selected. Typically, the capillary tube is coiled and is four or five spirals wide (especially when longer guide wires are packaged). The wire resides within the lumen of the spiraled capillary tube. Each pass of the capillary tube passes inside its previous spiral and so on until the spiral stops at some point. Frequently, there is a separate 4–5 inch single tubular section of additional coil to restrain the end of the wire clipped inside the rest of the coil. Each coil of tube can move independently of the other coils of the tube. Thus, it is necessary to restrain the independent movement of each individual coil of the tube, which is typically accomplished by fastening the coils together with a plurality of individual, multi-toothed clips. Each clip typically has between 4 and 5 C-shaped extensions or teeth that are manually snapped or clipped onto each individual coil to hold the coils in place.
This system has several drawbacks. For example, the coils are easily deformable, thus the necessity of manually placing the clips onto the coils, and this process is labor and cost intensive. Also, the clips can and do come loose and thus the coiled tube may become uncoiled thereby threatening sterility during both use and transport, or the tube may simply become difficult to use in the operating room. Additionally, when the clipped, multi-coiled tube is gripped by the hand the coils tend to collapse on each other and the palm is not large enough to maintain a sufficient grip when that happens. This can and does complicate the removal of the guide wire from the tube. Additionally, it is necessary with this type of wire containment system to have an assembly line of workers placing individual clips symmetrically about the coiled capillary plastic tubing either before or after inserting the guide-wire. In addition, the plastic coil itself has to be extruded and then coiled before the clips can be applied. This type of containment system is labor intensive and therefore expensive to produce and clinically uncomfortable to use because the system is not designed with any ergonomic considerations.
Also, when removing the guide wire, the inner surface of the coiled plastic tubing and the guide wire bind with considerable friction and it is necessary to inject saline into the plastic tubing to reduce the friction and make extraction of the wire easier. Even when this is done the wire still has a tendency to bind and can be difficult to remove from the tube. Further, it is usually impractical to reinsert the guide wire into the plastic tube because the tube wall binds with the outer coil of the guide wire and friction prevents the wire from being reloaded. So, once the guide wire is removed from the tube, if not immediately used, the wire is placed in a bowl of saline under a laparotomy sponge or is simply placed under a wet lap until required. Sometimes during these procedures, the guide wire will spring loose and can become unsterile necessitating a new wire.